1. Field of the Invention
The present invention relates to a man-hour management system which manages man-hours for producing a product, and more particularly to a man-hour management system which offers man-hour information effective to diminish the numbers of man-hours in each individual process unit and between processes.
2. Description of the Related Art
In case of producing a product, processes and works or jobs in each process are managed in terms of man-hours in order to grasp how much labor is required for the production of the product. Besides, how a production cost is curtailed becomes important in the case of producing the product, and diminution in the number of man-hours is very effective for curtailing the production cost. Therefore, techniques for calculating the man-hours and managing them become very important for judging the degrees to which the arrangement of workers or operators, diminution in the number of wasteful man-hours, process organization, etc. in a production line contribute to the curtailment of the production cost and the achievement of a target production cost. In each manufacturer, accordingly, man-hours are managed by a man-hour management system utilizing various techniques, and they are analyzed on the basis of man-hour information delivered from the man-hour management system.
A man-hour analysis in the prior art is such that a process is separated into personal works and equipmental works, and that net man-hours are respectively cumulated for the works by persons and the works by equipment so as to be compared. By way of example, FIG. 44 shows a graph of net man-hours for respective works in one process as is utilized in the prior-art man-hour analysis. In the graph 100, the works of personal man-hours 101 and equipmental man-hours 102 are listed in a vertical direction, while the net man-hours for the respective works are cumulated in a horizontal direction. In the man-hour analysis based on the graph 100, the magnitudes of the net man-hours extending horizontally are compared, and works of large net man-hours (for example, a work by a welding robot 1 and a component preparing work) are narrowed down as works which are subjects for diminutions in the numbers of man-hours. Besides, automation, the enhancement of an equipment precision, the reconsideration of a personal work procedure, or the like is promoted for such a work narrowed down, so as to attain diminution in the number of net man-hours, in turn, curtailment in a production cost.
Since, however, the prior-art man-hour analysis is made for the individual works, it is alien to an analysis for overall man-hours required for one cycle in each actual process (the total man-hours of net man-hours and loss man-hours in each process in one cycle of product production). Therefore, the prior-art man-hour analysis cannot analyze man-hours in each individual process unit, between processes or in view of the whole production line. More specifically, it cannot analyze man-hours in the case where a certain work is transferred to the next work, or where a certain process is transferred to the next process. Further, it cannot analyze man-hours for the state between works proceeding concurrently or for the state between processes proceeding concurrently. Accordingly, a man-hour management system in the prior art is difficult to make a man-hour analysis for determining process organization, the arrangement of equipment within a factory, the arrangement of workers in a production line, or the like, in each individual process unit or in consideration of the state between processes. Consequently, it is difficult to efficiently curtail a production cost.